Qtech QSW-8200-28T-AC-DC [8/74] Match as path

User Manual

Chapter 1. Commands for Routing Policy 8

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the sequence of matching check in the prefix-list. In the matching process the switch

check in turn every items identified by “sequence-number” ascending. Once certain

item obtains the conditions then the prefix-list filter is passed (without proceeding into

the next item check).

 Attentions should be paid on that at least one item match mode should be “permit”

when more than one prefix-list items is defined. The deny mode items can be

previously defined so to remove the unsuitable routing messages fast. However if all

items are at deny mode then none of the routes would be able to pass the filter of this

prefix-list. We here can define a “permit 0.0.0.0/0 ge 0 le 32” item after several defined

“deny mode” items so to grant the passage for all other routing messages.

 Example:

 Switch#config terminal

 Switch(config)#ip prefix-list mylist seq 12345 deny 10.0.0.0/8 le 22 ge 14

1.3 ip prefix-list sequence-number

 Command: ip prefix-list sequence-number

 no ip prefix-list sequence-number

 Function: Enable the sequence-number auto-creation function, the “no ip prefix-list

sequence-number” command closes the prefix-list sequence-number.

 Parameter: None.

 Default: Sequence-number auto-creation enabled.

 Command Mode: Global Mode

 Usage Guide: The command can be used to close the prefix-list sequence-number.

 Example:

 Switch(config)#no ip prefix-list sequence-number

1.4 match as-path

 Command: match as-path <list-name>

 no match as-path [<list-name>]

 Function: Configure the AS path domain for matching the BGP routing messages. The

“no match as-path [<list-name>]” deletes this configuration.

 Parameter: <list-name > is the name of access-list.

 Command Mode: route-map mode

 Usage Guide: This command matches the AS path domain of the BGP routing message

following the rules specified in the as-path list. If the matching succeeded, then the

“permit” or “deny” action in the route-map is performed.

 Example:

 Switch#config terminal

 Switch(config)#route-map r1 permit 5

 Switch(config-route-map)#match as-path 60